$('#el').prop('disabled', (i, v) => !v);
The .prop() method accepts two arguments:
- Property name (disabled, checked, selected) anything that is either true or false
- Property value, can be:
- (empty) – returns the current value.
- boolean (true/false) – sets the property value.
- function – Is executed for each found element, the returned value is used to set the property. There are two arguments passed; the first argument is the index (0, 1, 2, increases for each found element). The second argument is the current value of the element (true/false).
So in this case, I used a function that supplied me the index (i) and the current value (v), then I returned the opposite of the current value, so the property state is reversed.